How to view a javascript alert dialog in Calibre

avnermoshkovitz · 07-19-2021, 06:56 PM

I have an ebook that loads javascript code and it works ok with Calibre.
However, one of the commands is "alert()" and for this command I see the message:

Code:

ERROR: ... Ignored call to 'alert()'. The document is sandboxed, and the 'allow-modals' keyword is not set.

Is it possible to use iframe with attribute sandbox="allow-modal" within the page, e.g.

Code:

cat EPUB/xhtml/raw/ch1.xhtml 
...
<iframe sandbox="allow-modal">
  ...
</iframe>

to show the alert?

Or is the page itself sandboxed, so this will not help?
If the page itself is sandboxed, is there a way to indicate allow-modal to Calibre?

I'm basically trying to get some feedback from an ebook that runs properly in the desktop but does not run ok in mobile, when run via Calibre Content Server.

Thanks,
Avner

avnermoshkovitz · 07-19-2021, 07:39 PM

I tried using
https://www.mobileread.com/forums/sh...58&postcount=4

Code:

QTWEBENGINE_CHROMIUM_FLAGS="--no-sandbox" ebook-viewer

without success.

kovidgoyal · 07-19-2021, 10:26 PM

As I told you in the other thread, the book content is rendered in a sandboxed iframe. There is no way around that. If it were not the case JS in the book would be able to manipulate the library.

lcocea · Today, 10:35 AM

This is just to say that I agree support for the JavaScript confirmation/alert dialogs would be a very useful feature to have in the calibre Viewer. I particularly like the local storage support in the calibre Viewer. Both features are available in the Apple Books app.

lcocea · Today, 05:31 PM

...however, the calibre Viewer does not seem to persist the saved values between sessions, which beats the purpose of the localStorage feature.

07-19-2021, 06:56 PM	#1
avnermoshkovitz Member Posts: 22 Karma: 10 Join Date: Jun 2021 Device: Any ereader for Android or iOS	How to view a javascript alert dialog in Calibre I have an ebook that loads javascript code and it works ok with Calibre. However, one of the commands is "alert()" and for this command I see the message: Code: ERROR: ... Ignored call to 'alert()'. The document is sandboxed, and the 'allow-modals' keyword is not set. Is it possible to use iframe with attribute sandbox="allow-modal" within the page, e.g. Code: cat EPUB/xhtml/raw/ch1.xhtml ... <iframe sandbox="allow-modal"> ... </iframe> to show the alert? Or is the page itself sandboxed, so this will not help? If the page itself is sandboxed, is there a way to indicate allow-modal to Calibre? I'm basically trying to get some feedback from an ebook that runs properly in the desktop but does not run ok in mobile, when run via Calibre Content Server. Thanks, Avner

07-19-2021, 07:39 PM	#2
avnermoshkovitz Member Posts: 22 Karma: 10 Join Date: Jun 2021 Device: Any ereader for Android or iOS	I tried using https://www.mobileread.com/forums/sh...58&postcount=4 Code: QTWEBENGINE_CHROMIUM_FLAGS="--no-sandbox" ebook-viewer without success.

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07-19-2021, 10:26 PM	#3
kovidgoyal creator of calibre Posts: 45,308 Karma: 27111242 Join Date: Oct 2006 Location: Mumbai, India Device: Various	As I told you in the other thread, the book content is rendered in a sandboxed iframe. There is no way around that. If it were not the case JS in the book would be able to manipulate the library.

Today, 10:35 AM	#4
lcocea Junior Member Posts: 5 Karma: 10 Join Date: Jun 2025 Device: Readium	This is just to say that I agree support for the JavaScript confirmation/alert dialogs would be a very useful feature to have in the calibre Viewer. I particularly like the local storage support in the calibre Viewer. Both features are available in the Apple Books app.

Today, 05:31 PM	#5
lcocea Junior Member Posts: 5 Karma: 10 Join Date: Jun 2025 Device: Readium	...however, the calibre Viewer does not seem to persist the saved values between sessions, which beats the purpose of the localStorage feature.